Isolated singularities in the heat equation behaving like fractional Brownian motions

Mikihiro Fujii; Izumi Okada; Eiji Yanagida

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arXiv · 2012.04453

Isolated singularities in the heat equation behaving like fractional Brownian motions

Mikihiro Fujii·Izumi Okada·Eiji Yanagida

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Abstract

We consider solutions of the linear heat equation in $\mathbb{R}^N$ with isolated singularities. It is assumed that the position of a singular point depends on time and is H\"older continuous with the exponent $\alpha \in (0,1)$. We show that any isolated singularity is removable if it is weaker than a certain order depending on $\alpha$. We also show the optimality of the removability condition by showing the existence of a solution with a nonremovable singularity. These results are applied to the case where the singular point behaves like a fractional Brownian motion with the Hurst exponent $H \in (0,1/2] $. It turns out that $H=1/N$ is critical.

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Mikihiro Fujii, Izumi Okada, Eiji Yanagida. 2020-12-08. Isolated singularities in the heat equation behaving like fractional Brownian motions. https://arxiv.org/abs/2012.04453

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